Supercharged motorcycle

ABSTRACT

A supercharged motorcycle ( 10 ) configured for mounted operation by a rider (R) is disclosed. The supercharged motorcycle ( 10 ) broadly includes a motorcycle ( 12 ) and an air induction system ( 14 ) configured to deliver compressed induction fluid to the intake manifold ( 48 ) of the motorcycle&#39;s engine ( 18 ). The air induction system ( 14 ) broadly includes an air intake assembly ( 62 ) for receiving ambient air and delivering it downstream, a supercharger ( 64 ) in downstream communication with the air intake assembly ( 62 ) for compressing the air, an air delivery assembly ( 66 ) for delivering the compressed air to the engine ( 18 ), and a drive assembly ( 68 ) for powering the supercharger ( 64 ) off of the drive train ( 44 ). The entire air induction system ( 14 ) is positioned entirely outside of the leg-receiving areas (ALR) defined by the motorcycle ( 12 ) so as to not engage the rider&#39;s legs (L) and feet (F), when the rider (R) is mounted on the seat ( 34 ) in the normal operating position. Driving the air induction system ( 14 ) off of one or more components of the drive train ( 44 ) cooperates with the forward positioning of the supercharger ( 64 ) and the sleek configuration of the drive assembly ( 68 ) extending there between to provide an air induction system ( 14 ) that does not undesirably alter the overall appearance or sound of the motorcycle  12  and does not interfere with the preferred operation thereof as is preferred by motorcycle riders, particularly Harley-Davidson® riders. A preferred alternative embodiment of the power take-off subassembly for an air induction system for a supercharged motorcycle is also disclosed in the supercharged motorcycle ( 400 ). The motorcycle ( 400 ) includes a breakaway coupler assembly ( 408 ) that enables the motorcycle&#39;s drive train to continue operation in the event of catastrophic failure of the air induction system.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates generally to superchargers for providingincreased airflow to the engine of a motorcycle, such as a V-twin enginetypically found on a Harley-Davidson® motorcycle. More specifically, thepresent invention concerns an improved drive assembly that compactlyspans the drive train components of the motorcycle while remainingentirely inboard of, and thus does not interfere with, the rider'sanatomical engagement with the motorcycle. The unique drive assemblyenables the supercharger to be positioned in the otherwise unused spacein the fore area of the motorcycle chassis and can be driven off of abreakaway power take-off drivingly communicating with a selectedcomponent of the generally aftward drive train of the motorcycle.

2. Discussion of Prior Art

It is known in the art to supercharge an internal combustion engine toprovide increased airflow to the engine to thereby enhance the poweroutput of the engine. There are several types of superchargers known inthe art, including, for example, Roots-type superchargers andcentrifugal superchargers, both of which are driven off of thecrankshaft of the engine, as well as turbochargers that are driven offof the engine's exhaust. One exemplary centrifugal supercharger welladvanced in the art and particularly resistant to failure is disclosedin the copending U.S. Application for Letters patent Ser. No. 10/641,619entitled CENTRIFUGAL COMPRESSOR WITH IMPROVED LUBRICATION SYSTEM FORGEAR-TYPE TRANSMISSION, filed Aug. 14, 2003 (the “Jones '619application”), having a common inventor and assignee with the presentapplication and hereby incorporated by reference herein.

It is also known in the art to supercharge a motorcycle engine,including the distinctive V-twin engine design found on Harley-Davidson®motorcycles. However, motorcycle engines and particularlyHarley-Davidson® V-twin motorcycle engines provide several problems forsupercharging applications. For example, superchargers are typicallydriven off of the engine's crankshaft, however, the crankshaft istypically positioned adjacent the footboard and foot controls of themotorcycle and therefore there is very limited space in and around thecrankshaft in which to position drive components. Therefore, in order toplace the drive components and/or the supercharger itself in the crowdedarea around the crankshaft, the components can undesirably alter orinterfere with the rider's otherwise normal, comfortable operatingposition and/or the rider's ability to readily manipulate the footcontrols. Additionally, it has been determined that Harley-Davidson®owners in particular are loathe to modify their motorcycles in any waythat will materially alter or affect the original distinctive appearanceand sound of the motorcycle. Furthermore, prior art superchargers,particularly superchargers that do not utilize multiple bearingarrangements or a self-contained dedicated lubrication system, can besubject to premature failure, or failure prior to the life expectancy ofthe motorcycle's engine, particularly where the drive assembly is notmaintained within very tight tolerances. Failure of these prior artsuperchargers can be problematic as it may in turn cause catastrophic,and thus costly, engine failure as well. The potential for such enginefailure is exacerbated where the supercharger is directly integratedwith the engine, such as sharing a common lubrication system, as foreigndebris occasioned by supercharger failure can leak into the internalcomponents of the engine. It has recently been determined that theseproblems are exacerbated by the large degree of “slop” associated withthe flywheel, thus limiting the prior art superchargers to direct drivesystems that take power directly off of the crankshaft. Some of theseproblems, as well as others, associated with supercharging a V-twinmotorcycle engine are discussed in U.S. Pat. No. 6,105,558 entitledSUPERCHARGING APPARATUS, issued Aug. 22, 2000.

All prior art supercharged motorcycles, including the superchargingsystem disclosed in the '558 patent, are problematic and subject toseveral undesirable limitations. For example, all prior artsuperchargers are driven directly off of the crankshaft and accordinglyrequire drive components, and in most cases, the supercharger housingitself, to be positioned on, above, and/or outboard of the crankshaft.Such positioning is undesirable as these components project into theleg-receiving area of the motorcycle where the rider's legs wouldotherwise be located during normal operation thereby interfering withthe rider's comfort and operation of the motorcycle. Additionally, suchpositioning undesirably alters the otherwise smooth aesthetic look ofthe already crowded engine and crankshaft area. Accordingly, there is aneed for an improved supercharger system for a motorcycle that does notinterfere with the rider's normal operating position or materially alterthe overall appearance and sound of the motorcycle and does not causeengine damage in the event of a catastrophic failure of the system.

SUMMARY OF INVENTION

The present invention provides an improved supercharged motorcycle thatdoes not suffer from the problems and limitations of the prior artsupercharged motorcycles detailed above. The inventive superchargedmotorcycle includes an improved drive assembly that compactly spans thedrive train components of the motorcycle while remaining entirelyinboard of, and thus does not interfere with, the rider's anatomicalengagement with the motorcycle. The unique drive assembly enables thesupercharger to be positioned in the otherwise unused space in the forearea of the motorcycle chassis and driven off of a selected component ofthe generally aftward drive train of the motorcycle. Preferredembodiments of the drive assembly include a breakaway power take-offdrivingly communicating the supercharger's impeller and the motorcycle'sdrive train so that failure of one does not impact the other.

A first aspect of the present invention concerns a superchargedmotorcycle broadly including a front wheel, a rear wheel longitudinallyspaced from the front wheel, an engine including a rotatable crankshaftgenerally positioned between the wheels, and an air induction systemoperable to deliver compressed induction fluid to the engine. The airinduction system includes a supercharger and a drive assembly drivinglyconnecting the supercharger and the crankshaft. The supercharger islongitudinally spaced forward of the crankshaft to define a fore areatherebetween. The drive assembly spans the fore area.

A second aspect of the present invention concerns a superchargedmotorcycle for mounted operation by a rider. The motorcycle broadlyincludes a chassis operable to be mounted by the rider in a normaloperating position, an engine, and an air induction system operable todeliver compressed induction fluid to the engine. The chassis includes afront wheel, a rear wheel longitudinally spaced from the front wheel, aframe supported between the wheels, a gas tank spaced between thewheels, a seat positioned aft of the gas tank and configured to supportthe rider in the normal operating position, and a pair of footboardsspaced on either side of the frame and positioned generally below thegas tank and the seat. The engine includes a rotatable crankshaftgenerally positioned between the wheels. The air induction systemincludes a supercharger and a drive assembly drivingly connected to thesupercharger and the engine to supply power from the engine to thesupercharger. The chassis and engine cooperate to define a pair ofleg-receiving areas spaced on either side of the chassis and each beingoperable to receive a corresponding leg of the rider when the rider ismounted on the seat in the normal operating position. Each of theleg-receiving areas is generally defined by a curvilinear leg pathextending between the seat and a respective one of the footboards thatmimics the corresponding rider's leg when the rider is mounted on theseat in the normal operating position. The entire air induction systemis positioned outside of the leg-receiving areas with at least a portionof the air induction system extending between the leg paths.

A third aspect of the present invention concerns a method ofsupercharging a motorcycle broadly including the steps of determining agenerally normal operating position for a rider operating the motorcyclewhile mounted thereon wherein the rider's legs are received in a pair ofleg-receiving areas spaced on either side of the chassis of themotorcycle, providing an air induction system to deliver compressedinduction fluid to the engine of the motorcycle, and positioning the airinduction system on the chassis so that the entire air induction systemis outside of the leg-receiving areas.

A fourth aspect of the present invention concerns a superchargedmotorcycle broadly including a chassis operable to be mounted by a riderand including a front wheel and a rear wheel longitudinally spaced fromthe front wheel, an engine including a rotatable crankshaft generallypositioned between the wheels, a drive train drivingly interconnectingthe crankshaft and the rear wheel and including a rotatable drivenelement longitudinally spaced from the crankshaft and an endless elementdrivingly interconnecting the crankshaft and the driven element, and anair induction system operable to deliver compressed induction fluid tothe engine. The air induction system includes a supercharger and a driveassembly. The drive assembly drivingly interconnects the drive train andthe supercharger and includes an indirect power take-off componentdrivingly engaging one of the driven and endless elements.

A fifth aspect of the present invention concerns a supercharged vehiclebroadly including a chassis, an engine, and an air induction systemoperable to deliver compressed induction fluid to the engine andincluding a supercharger and a supercharger drive. The superchargerdrive drivingly interconnects the engine and the supercharger. The driveincludes first and second rotatable drive members that cooperate totransfer driving power from the engine to the supercharger. The drivefurther includes a breakaway coupler assembly selectivelyinterconnecting the drive members so that the members are normallydrivingly connected by the coupler assembly under a variable torsionforce. The coupler assembly is configured to drivingly disconnect themembers and enable the members to rotate independently of one anotherfor at least one revolution when the torsion force exceeds apredetermined value.

A sixth aspect of the present invention concerns a method ofsupercharging a motorcycle broadly including the steps of rotatablydriving the motorcycle's crankshaft off of the motorcycle's engine,simultaneously rotatably driving an impeller off of the motorcycle'scrankshaft to compress induction fluid for the motorcycle's engine whenthe crankshaft is rotated, and preventing one of the impeller andcrankshaft from rotating while the other one continues to rotate.

Other aspects and advantages of the present invention will be apparentfrom the following detailed description of the preferred embodiments andthe accompanying drawing figures.

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the invention are described in detail belowwith reference to the attached drawing figures, wherein:

FIG. 1 is a right side elevational view of a supercharged motorcycleconstructed in accordance with the principles of a preferred embodimentof the present invention;

FIG. 2 is a left side elevational view of the supercharged motorcycleillustrated in FIG. 1;

FIG. 3 is an enlarged partially exploded front perspective view of themajor components of the air induction system of the superchargedmotorcycle illustrated in FIGS. 1 and 2 shown supported on themotorcycle's modified crankcase cover (shown with a portion removed) andillustrated with the motorcycle's foot controls and left footboard;

FIG. 4 is an enlarged back perspective view the air induction system asillustrated in FIG. 3 illustrating the components of the drive assemblyand their interconnection with the motorcycle's flywheel;

FIG. 5 is a partial perspective view of the supercharged motorcycleillustrated in FIGS. 1–4 showing the positioning of the air inductionsystem entirely outside of the motorcycle's left side leg-receivingarea;

FIG. 6 is a partial top perspective view of the supercharged motorcycleillustrated in FIGS. 1–5 showing the portion of the drive assembly ofthe air induction system that spans the leg-receiving areas beingpositioned entirely inboard of the leg-receiving areas;

FIG. 7 is a partial front perspective view of the superchargedmotorcycle illustrated in FIGS. 1–6 shown with a rider mounted on theseat in the normal operating position illustrating that the entire airinduction system is spaced from the rider's legs in the normal operatingposition so as not to engage or interfere therewith;

FIG. 8 is a is a partial rear perspective view of the superchargedmotorcycle illustrated in FIGS. 1–7 shown with the rider mounted on theseat in the normal operating position illustrating the drive assemblyspanning between the rider's legs and being positioned entirely inboardthereof;

FIG. 9 is a partial side elevational view of a supercharged motorcycleconstructed in accordance with the principles of a preferred alternativeembodiment of the present invention and illustrating the power take-offof the air induction system's drive assembly drivingly engaging the beltof the motorcycle's drive train;

FIG. 10 is a partial side elevational view of a supercharged motorcycleconstructed in accordance with the principles of a second preferredalternative embodiment of the present invention and illustrating thepower take-off of the air induction system's drive assembly drivinglyengaging the chain of the motorcycle's drive train;

FIG. 11 is a partial perspective view of a supercharged motorcycleconstructed in accordance with the principles of a third preferredalternative embodiment of the present invention and illustrating a firstdrive gear of the power take-off of the air induction system's driveassembly drivingly engaging the flywheel of the motorcycle's drive trainand being coupled to a second drive gear with a breakaway coupler;

FIG. 12 is an enlarged exploded assembly view of the air inductionsystem's power take-off of the supercharged motorcycle illustrated inFIG. 11 showing the assembly of the breakaway coupler with the first andsecond drive gears; and

FIG. 13 is similar to FIG. 12 and is an enlarged exploded assembly viewof the power take-off illustrated in FIGS. 11 and 12 showing theassembly of the break away coupler with the first and second drivegears.

DETAILED DESCRIPTION

FIG. 1 illustrates a supercharged motorcycle 10 constructed inaccordance with the principles of a preferred embodiment of the presentinvention and configured for mounted operation by a rider R (see FIGS.7–8). As further detailed below, the principles of the present inventionare particularly well suited for V-twin engines, such as theHarley-Davidson® V-twin engine illustrated in FIGS. 1–8. However, theprinciples of the present invention are not limited to any particulartype of motorcycle engine and equally apply to virtually any type ofengine on virtually any brand of motorcycle. Furthermore, many of theaspects of the present invention also apply to other all-terrain typevehicles, such as three-wheeled and four-wheeled vehicles wherein therider straddles the chassis of the vehicle in a mounted operatingposition. The illustrated supercharged motorcycle 10 broadly includes amotorcycle 12 and an air induction system 14 configured to delivercompressed induction fluid to the motorcycle's engine (see FIGS. 1 and2).

Turning initially to FIGS. 1–2 and 5–8, the illustrated motorcycle 12broadly includes a chassis 16 operable to be mounted by the rider R, anengine 18 supported on the chassis 16 for powering the chassis 16 in aforward direction, and a body 20 supported on the chassis 16. Themotorcycle 12 is a conventional motorcycle, such as one typicallyavailable from an OEM, and in this regard will only be briefly describedwith the understanding that the motorcycle 12 could include virtuallyany conventional components in virtually any manner known in the art.The chassis 16 includes aligned longitudinally spaced front and rearwheels 22 and 24, respectively, and a frame 26 supported between thewheels 22,24. The frame 26 is supported on the front wheel 22 by a fork28 that can be manipulated to steer the motorcycle 12 by handlebars 30.The chassis 16 further includes a gas tank 32 spaced between the wheels22,24 and supported on the frame 26 and a seat 34 positioned aft of thegas tank 32 and configured to support the rider R on the motorcycle 12.The illustrated chassis 16 also includes a pair of footboards 36 and 38spaced on either side of the frame 26 and positioned generally below thegas tank 32 and the seat 34 for supporting the feet F of the rider Rwhen mounted on the motorcycle 12 (see FIGS. 7 and 8). The footboards36,38 are virtually identically configured and therefore only thefootboard 36 will be described in detail with the understanding that thefootboard 38 is similarly constructed. The footboard 36 presents a topfoot-supporting surface 36 a for supporting the foot F of the rider R.The surface 36 a defines an outermost edge 36 b laterally spaced fromthe frame 26 and an innermost edge 36 c adjacent the frame 26. In onemanner known in the art, the motorcycle 12 includes foot controls 40,such as for shifting gears and the like, that are positioned adjacentthe footboard 36 (see FIGS. 5–8). Although the foot-supporting surface36 a is configured to receive the entire foot F of the rider R, in onemanner known in the art, the footboards 36,38 could also be simple pegsthat present a relatively smaller foot-supporting surface.

The chassis 16 could be variously configured in any manner known in theart, however, it is important that the chassis 16 be configured tosupport the rider R in a normal operating position. A normal operatingposition is shown in FIGS. 7 and 8 wherein the rider R is sitting on theseat 34 so the rider's hands can reach the handlebars 30 and the rider'sfeet F are supported on the footrests 36,38 where they can readily andselectively activate the foot controls 40. In this regard, as shown inFIGS. 5 and 6, the motorcycle 12 naturally defines a pair ofleg-receiving areas ALR spaced on either side of the chassis 16 and eachreceiving a corresponding leg L of the rider R when the rider R ismounted on the seat 34 in the normal operating position. In theillustrated motorcycle 12, the chassis 16 and the engine 18 cooperate todefine the leg-receiving areas ALR. In this regard the leg-receivingareas ALR generally extend from the footrests 36,38 to the seat 34 andhave a forward boundary determined along the tapered portion of the gastank 32 and an aftward boundary determined along the tapered portion ofthe seat 34 (see FIG. 6). Each of the leg-receiving areas ALR isgenerally defined by a curvilinear, somewhat U-shaped leg path PL (seeFIGS. 1–2 and 7–8) extending between the seat 34 and a respective one ofthe footrests 36,38 that mimics the corresponding rider's leg L when therider R is mounted on the seat 34 in the normal operating position. Inthe illustrated motorcycle 12, the gas tank 32 defines a pair oflaterally outermost rider-engaging contact points CP oppositely spacedon either side of the chassis 16 that engage the rider's legs L, and inthis case, the knee of the rider's legs L when the rider R is mounted onthe seat 34 in the normal operating position (see FIG. 7). However, fordifferently configured motorcycles, the contact points CP could bedefined on components of the chassis 16 other than the gas tank 34, suchas the frame 26, or on the body 20 for example. Each of the contactpoints CP is positioned along a respective one of the leg paths PL. Eachof the contact points CP lies in a common plane with a respective one ofthe innermost edges, such as innermost edge 36 c. Each of the leg pathsPL also lies in a respective one of the common planes. In theillustrated motorcycle 12, the common planes angle in slightly from theinnermost edges 36 c to the contact points CP and define the inboardboundaries of the leg-receiving areas ALR.

It will be appreciated that the leg-receiving areas ALR may varyslightly from motorcycle to motorcycle depending on the make and modelof the motorcycle. However, every motorcycle will define leg-receivingareas ALR. These areas ALR will in large part be determined by the legpaths PL defined by the rider's legs L when seated on the motorcycle inthe normal operating position and the anatomical positioning of therider therein. That is to say, when seated on the motorcycle in thenormal operating position, a rider's feet will be spread apart a certaindistance, typically ranging between about eighteen and forty-two inchesand the rider's knees will be spread apart a lesser distance, typicallyranging between about twelve and thirty-six inches. Accordingly, therider's lower leg region between the knee and the foot will be angledinward slightly from the foot to the knee, typically ranging betweenabout five and thirty-five degrees. This anatomical angle mimics theangle of the common planes detailed above relative to the horizontalcenter plane of the motorcycle.

The engine 18 is rigidly mounted in the frame 26 and in one manner wellknown in the art, includes a crankshaft 42 drivingly connected to therear wheel 24 by a drive train 44 (see FIGS. 2 and 4). The engine 18 isfuel injected and includes an electronic fuel injection apparatus 46 incommunication with an intake manifold 48. However, the engine 18 couldbe carbureted and need not be fuel injected. The drive train 44 includesa motorcycle power take-off shaft 50 that is fixed to a pair of drivensprockets 50 a that are driven by the crankshaft 42 (see FIG. 4). In onemanner known in the art, the illustrated driven sprockets 50 a aredriven by the crankshaft 42 by a pair of endless chains 52. The powertake-off shaft 50 in turn drives the rear wheel 24 by a drive chain orbelt (not shown). As is known in the art, the power take-off shaft 50drives the drive chain through a geared transmission 54 (e.g., fourspeed, five speed, etc.) controlled by a clutch (not shown) that isoperated by the foot controls 40. The illustrated drive train 44 furtherincludes a toothed flywheel 56 that is fixed to the power take-off shaft50 and to a starter motor 58 (see FIG. 4). The engine 18 and the drivetrain 44 could be variously configured in any manner known in the artand could include for example a belt driven power take-off shaft.

The body 20 is supported on the chassis 16. The illustrated body 20includes a pair of fenders covering the front and rear wheels 22,24.However, the body 20 could be variously configured and include forexample more substantial body fairing. In this regard, the body 20 coulddefine the laterally outermost contact points CP along the leg paths PL.

The illustrated motorcycle 12 is a Harley-Davidson®2001 Softail Fatboywith a rigid mount 1450 cc V-twin Twin Cam 88B balanced engine withelectronic fuel injection. The principles of the present invention areparticularly well suited for supercharging Harley-Davidson® V-twinengines and as further detailed below, solves many of the prior artproblems that have frustrated, if not virtually made impossible,successful supercharger applications for these engines. However, theprinciples of the present invention are equally applicable to virtuallyany motorcycle engine and in this regard the motorcycle 12 could be anyconventional motorcycle as is available from numerous OEMs.

It will be appreciated that the conventional motorcycle 12 has beenmodified with the air induction system 14 to arrive at the superchargedmotorcycle 10. In this regard, the crankcase's side cover 60 has beenmodified to house some of the components of the air induction system 14as will be subsequently be described. One or both of the modifiedcrankcase side cover 60 and the air induction system 14 could beoriginally manufactured on the motorcycle 12, for example by the OEM, orthese components could be retrofit after market, such as by the enduser.

Turning to FIGS. 3–8, the illustrated air induction system 14 isconfigured to deliver compressed induction fluid to the intake manifold48 of the engine 18 and broadly includes an air intake assembly 62 forreceiving ambient air and delivering it downstream, a supercharger 64 indownstream communication with the air intake assembly 62 for compressingthe air, an air delivery assembly 66 for delivering the compressed airto the engine 18, and a drive assembly 68 for powering the supercharger64 off of the drive train 44. In more detail, the air intake assembly 62receives ambient air through a filter 70 and delivers the filtered airdownstream to the supercharger 64. It will be appreciated that theillustrated air intake assembly 62 is positioned forward of thesupercharger 64 and towards the front of the motorcycle 12 to facilitatereceipt of a fresh supply of ambient air. However, the air intakeassembly 62 could be alternatively positioned. Although some type offilter is preferred, the air intake assembly is not necessary and thesupercharger 64 could receive air directly from the atmosphere.

The supercharger 64 intakes the filtered air from the air intakeassembly 62, compresses the air, and delivers the compressed air to theair delivery assembly 66. In more detail, the illustrated supercharger64 is a centrifugal supercharger including a rotatable impeller housedin a volute case that compresses the air when rotated. In one mannerknown in the art, the impeller is rotated at significantly higher rpmthan the crankshaft 42. In this regard, as further detailed below, thedrive assembly 68 is preferably a step-up drive mechanism. However, thesupercharger 64 preferably additionally includes a step-up transmissionthat facilitates the desired high rotational speeds of the impeller.Given the high operational speeds of the impeller and the attendantloads on the internal components of the supercharger 64 coupled with theundesirable impact of catastrophic failure of the supercharger 64, thesupercharger 64 preferably includes an impeller shaft supported by avelocity variance-reducing multiple bearing arrangement and a dedicatedlubrication system for lubricating the internal components of thesupercharger 64. Suitable preferred multiple bearing arrangements aredisclosed in applicant's U.S. Pat. No. 6,478,469, issued Nov. 12, 2002,entitled VELOCITY VARIANCE REDUCING MULTIPLE BEARING ARRANGEMENT FORIMPELLER SHAFT OF CENTRIFUGAL SUPERCHARGER, as well as copendingapplications for U.S. Letters patent Ser. Nos. 09/683,871 and10/064,835, filed Feb. 26, 2002 and Aug. 22, 2002, respectively, bothbearing the same title as the '469 patent, all of which are herebyincorporated by reference herein. Suitable preferred self-containeddedicated lubrication systems are disclosed in the Jones '619application previously incorporated by reference herein. It is believeda supercharger having a multiple bearing arrangement and/or aself-contained, dedicated lubrication system reduces the risks ofpremature failure or in the event of such failure, reduces any attendantundesirable engine damage.

In order to maintain the overall original sound of the motorcycle 12,the supercharger 64 further preferably includes noise-reducingcomponents and/or features such as a noise-reducing impeller shaft. Asuitable noise dampening shaft construction is disclosed in applicant'sU.S. Pat. Nos. 6,478,016 and 6,516,788, issued Nov. 12, 2002 and Feb.11, 2003, respectively, both entitled GEAR DRIVEN SUPERCHARGER HAVINGNOISE REDUCING IMPELLER SHAFT, both of which are hereby incorporated byreference herein. It is believed the supercharger designs disclosed inthe above incorporated patents and applications combine to provide asupercharger capable of withstanding the operational loads somewhatunique to motorcycle applications, yet enables the supercharger tooperate at relatively low noise levels so as not to undesirably hinderthe original sound of the motorcycle. In particular, these superchargerdesigns provide superior long-lasting, durable superchargers that areunlikely to catastrophically fail and are therefore well suited formotorcycle applications. However, it is within the ambit of the presentinvention to utilize various additional features and/or components forthe centrifugal supercharger 64. For example, the supercharger 64 couldinclude a soft material insert within the case such as the one disclosedin applicant's copending application for U.S. Letters patent Ser. No.10/359,411, filed Jan. 22, 2003, entitled A METHOD AND APPARATUS FORINCREASING THE ADIABATIC EFFICIENCY OF A CENTRIFUGAL SUPERCHARGER, whichclaims the priority of provisional U.S. Application Ser. No. 60/430,814,filed Dec. 4, 2002 and bearing the same title, both of which are herebyincorporated by reference herein.

Although the above-described centrifugal supercharger is preferred, itis within the ambit of the present invention to utilize virtually anytype of compressor for pressurizing induction fluid for the engine 18.For example, the air induction system 14 could utilize a Roots-typeblower or even a turbocharger. However, for some aspects of the presentinvention, it is important that the compressor be driven off of thedrive train and not for example, a turbocharger that is driven off ofthe engine's exhaust.

Turning to FIGS. 1–2 and 7, the air delivery assembly 66 is in fluidcommunication with the supercharger 64 and the intake manifold 48 of theengine 18 and delivers the compressed air from the supercharger 64 tothe engine 18. In more detail, the illustrated air delivery system 66includes an air supply tube 72 and an intercooler 74 disposed along thetube 72. In one manner known in the art, the intercooler 74 cools thecompressed induction fluid prior to discharging the air into themanifold 48. In this regard, the intercooler 74 is positioned on theright side of the motorcycle 12 adjacent the inlet of the tube 72 intothe manifold 48. The intercooler 74 is an air cooled intercooler andthus is positioned adjacent the front of the motorcycle 12 so as tocommunicate with the fresh air drawn around the motorcycle 12 as themotorcycle 12 is propelled in the forward direction. The air deliveryassembly 66 could be alternatively configured. For example, the quantityof compressed air delivered to the intake manifold 48 could becontrolled by an inlet valve that varies the supply of air to thesupercharger in response to downstream air pressure conditions or at therider's discretion. Such an inlet valve is disclosed in applicant'scopending application for U.S. Letters patent Ser. No. 10/249,579, filedApr. 21, 2003, entitled AIR INDUCTION SYSTEM HAVING INLET VALVE, whichis hereby incorporated by reference herein. The air delivery assembly 66need not include an intercooler and could for example be configured sothat the supercharger 64 discharges compressed air directly into theintake manifold 48 without the need for extended tubing.

Returning to FIGS. 3–8, the illustrated drive assembly 68 powers thesupercharger 64 off of the drive train 44. The drive assembly 68 broadlyincludes a support housing 76, an indirect power take-off subassembly78, a driven sheave 80, a pair of idler sheaves 82 and 84, and anendless drive element 86 drivingly communicating the power take-offsubassembly 78 and the driven sheave 80. As shown in FIGS. 3 and 4, theillustrated support housing 76 cooperates with the modified side cover60 to support the other components of the air induction system 14 on theside cover 60. In more detail, the illustrated housing 76 includes agenerally flat elongated support bracket 88 that supports thesupercharger 64 on the side cover 60. The bracket 88 is fixed to agusset 90 on the modified side cover 60, such as by bolts or screws orthe like. The end of the bracket 88 proximate the supercharger 64includes a pair of spaced apart fingers 88 a and 88 b that receive aportion of the supercharger 64 therebetween (see FIG. 4). Thesupercharger 64 is also fixed to the proximate end of the bracket 88 bybolts or screws or the like. The distal end of the bracket 88 isarcuately configured so as to complement the profile of the side cover60 and the gusset 90 is offset from the backside of the side cover 60.In this manner, the bracket 88 overlaps and engages the top surface ofthe side cover 60 and is therefore supported thereby. The illustratedsupport housing 76 further includes a top plate 92 fixed along the topsurface of the bracket 88. The top plate 92 functions as a guard toprevent undesired items, such as the clothing of the rider R, from beingdrawn into, or interfering with, the moving components of the driveassembly 68. For purposes that will subsequently be described, theillustrated housing 76 further includes a support plate 94 fixed to theoutside of the side cover 60 with bolts or screws or the like (see FIG.3). In the illustrated air induction system 14, other than theengagement between the air supply tube 72 and the intake manifold 48,the air induction system 14 is supported on the motorcycle 12 by thesupport bracket 88 and the support plate 94 in cooperation with themodified side cover 60. It is within the ambit of the present inventionto utilize various alternatively configured support housings for the airinduction system 14, including configurations that use multiplebrackets. However, as will be further detailed below, it is importantfor some aspects of the invention that the support housing remains clearof the leg-receiving areas ALR defined by the motorcycle 12.

The illustrated drive assembly 68 is an indirect drive that is, thesupercharger 64 is not driven directly off of the crankshaft 42 as wellas a step-up drive that is, a drive that cooperates with thesupercharger's transmission to rotate the impeller of the supercharger64 at an increased rpm relative to the rpm of the crankshaft 42. In thisregard, the illustrated indirect power take-off subassembly 78 includesan undersized power take-off gear 96 that drivingly intermeshes with theflywheel 56 (see FIGS. 3 and 4). The gear 96 is fixed to a shaft 98 thatis in turn rotatably supported between the side cover 60 and the supportplate 94. The shaft 98 is supported by a pair of bearing assemblies(with only the bearing assembly 100 shown in FIG. 3) press fit withinrespective sockets (not shown) in the side cover 60 and support plate94. In the usual manner, a wavy spring washer 102 is provided in atleast one of the sockets. The bearing assemblies, including theillustrated assembly 100, are preloaded grease-packed bearings, however,any suitable bearing arrangement could be utilized. In the illustratedpower take-off subassembly 78, the power take-off gear 96 drivinglyintermeshes with a driven gear 104 (see FIG. 3) that is drivinglycoupled to a power take-off sheave 106, however, the sheave 106 could becoupled directly to the power take-off gear 96 without the need for theintermediate driven gear 104, depending on the desired rotationaldirection of the impeller of the supercharger 64. The gear 104, similarto the gear 96, is fixed to a shaft 108 that is rotatably supportedbetween the side cover 60 and the support plate 94 by bearing assemblies(with only the bearing assembly 110 being shown in FIG. 3). However,unlike the shaft 98, the shaft 108 is cantilevered to extend out of theinside of the side cover 60 where it is fixed to the power take-offsheave 106 (see FIG. 4). In this manner, when the flywheel 56 isrotated, the power take-off sheave 106 is also caused to rotate in thesame rotational direction but at a higher rpm. It is within the ambit ofthe present invention to utilize various alternative configurations forthe power take-off subassembly 78, for example, the power take-off gearcould intermesh with drive components of the motorcycle other than theflywheel 56. However, it is important for some aspects of the inventionthat the power take-off gear be driven by one or more components of thedrive train 44 (e.g., the power take-off shaft 50, the driven sprockets50 a, the chains 52, the transmission 54, the flywheel 56, etc.).

As previously indicated, the power take-off subassembly 78 drives thedriven sheave 80 via the endless drive element 86. In more detail, andas shown in FIG. 4, the illustrated endless drive element 86 is a beltthat encircles the sheaves 106 and 80 and entwines through the pair ofidler sheaves 82 and 84. The idler sheaves 82,84 are each rotatablysupported on the support bracket 88 in any suitable manner. In onemanner known in the art, the idler sheave 82 is adjustable relative tothe bracket 88 (e.g., via a slot 112 formed in the bracket 88 as shownin FIG. 2) to thereby adjust the tension in the belt 86. The drivensheave 80 is fixed to one end of a cantilevered shaft extending out ofthe housing of the supercharger 64 (e.g., the impeller shaft, atransmission shaft, etc.) so that the shaft is driven by the sheave 80.In this manner, when the flywheel 56 is rotated by the motorcycle engine18, the drive assembly 68 powers the supercharger 64 off of the engine18 at a stepped up rpm relative to the crankshaft 42. The belt drivesystem is preferred in that the belt 86 and sheaves 80,106 provide somedegree of give (e.g., the belt 86 will slip relative to the sheaves80,106, etc.) in the event of failure of the air induction system thatfacilitates reducing the risk of undesirable engine damage. However, thedrive assembly 68 could be alternatively configured and utilizedifferent endless elements entraining various driven components ratherthan the illustrated belt drive system that uses sheaves. The driveassembly 68 could also be configured to power the supercharger 64without utilizing an endless drive element, such as with a gear train,or the like.

Turning now to FIGS. 5–8, the air induction system 14, including thesupercharger 64 and the air intake, air delivery, and drive assemblies62,66,68, is positioned entirely outside of the leg-receiving areas ALRso as to not engage the rider R, including the rider's legs L and feetF, when the rider R is mounted on the seat 34 in the normal operatingposition. In more detail, in the illustrated air induction system 14,the supercharger 64 is forwardly spaced from the crankshaft 42 in theforward area of the motorcycle 12 defined between the crankshaft 42 andthe front wheel 22. The supercharger 64 is sufficiently spaced from thecrankshaft 42 to define a fore area therebetween. The power take-offsubassembly 78 is spaced aftwardly from the crankshaft 42 adjacent theflywheel 56 in the back area of the motorcycle 12 defined between thecrankshaft 42 and the rear wheel 24. The flywheel 56 is spaced from thecrankshaft 42 to define an aft area therebetween. The drive assembly 68spans between the back and forward areas of the motorcycle 12 and spansthe entire aft and fore areas defined around the crankshaft 42. In thismanner, at least a portion of the drive assembly 68 (e.g., portions ofthe housing 76, the belt 86 and the sheaves 82,84) extends between theleg paths PL. It is important to many aspects of the present inventionthat the portion of the air induction system 14 extending between theleg paths PL in the illustrated system 14 it is the portion of the driveassembly 68 just described is positioned entirely inboard of the legpaths PL so as to not interfere with the rider's legs L when the rider Ris seated on the seat 34 in the normal operating position. It will beappreciated that in the illustrated air induction system 14, the entiredrive assembly 68, including those portions not extending between theleg paths PL, is positioned entirely inboard of the common planes thatdefine the inboard boundaries of the leg-receiving areas ALR. The lowprofile configuration of the drive assembly 68 enables the relativelylarger components of the air induction system 14 to be placed outside ofthe forward and aftward boundaries of the leg-receiving areas ALR, forexample, the supercharger 64 is positioned ahead of the forward boundaryof the ALR and the power take-off subassembly 78 is positioned behindthe aftward boundary of the ALR.

It is believed that driving the air induction system 14 off of one ormore components of the drive train 44 rather than, for example, off ofthe crankshaft 42 cooperates with the forward positioning of thesupercharger 64 and the sleek configuration of the drive assembly 68extending there between provides an air induction system 14 that ispreferred by motorcycle riders, particularly Harley-Davidson® riders.That is to say, the illustrated air induction system 14 does notundesirably alter the overall appearance or sound of the motorcycle 12and does not interfere with the preferred, safe operation thereof.However, the air induction system 14 could be variously alternativelyconfigured. For example, the supercharger could be alternativelypositioned and driven off of components of the drive train other thanthe flywheel, or for some aspects of the invention, could be drivendirectly off of the crankshaft (although not preferred), and could bepositioned on the right side of the motorcycle.

In operation, the air induction system 14 must first be integrated ontothe motorcycle 12. As indicated above, this could be done by the OEM atthe time of manufacture. Otherwise, the crankcase's original side covermust first be removed, to expose the relevant components of the drivetrain 44. The modified crankcase side cover 60 is then fitted with thepower take-off gear 96 that is, the shaft 98 and bearing assembly areseated into the corresponding socket. For assembly purposes, the gear 96could be keyed to the shaft 98. In a similar manner, the driven gear 104is fitted into the cover 60 and intermeshed with the gear 96. Themodified side cover 60 is then bolted onto the motorcycle 12. Once thecover 60 is in place, the support plate 94 can be press fit with bearingassemblies 100,110 and the wavy spring washers, such as the washer 102.The plate 94 can then be bolted onto the side cover 60. Next, theremainder of the support housing 76 can be bolted onto the side cover 60that is, the top plate 92 can be bolted to the support bracket 88 and inturn the bracket 88 can be bolted to the gusset 90. The supercharger 64is then bolted onto the fingers 88 a,88 b of the bracket 88. Next, thebelt is entrained around the sheaves 80,82,84,106 and the sheaves arefixed onto their respective shafts and/or fixed to the bracket 88.Finally, the filter 70 is bolted onto the supercharger 64 and the airsupply tube 72 and intercooler 74 are fixed between the supercharger 64and the intake manifold 48. The supercharged motorcycle 10 is now readyfor use.

In use, the rider R mounts the motorcycle 10 so that the rider R isseated on the seat 34. The starter motor 58 can then be activated torotate the flywheel 56 to start the engine 18 of the motorcycle 10. Therider R can then activate the foot controls 40 to shift the motorcycle10 into a forward gear. The rider R can then operate the motorcycle 10while seated in the normal operation position with both feet F onrespective footboards 36,38 so that the legs L are received in theleg-receiving areas ALR. In the normal operating position, the rider'slegs L do not engage any part of the air induction system 14. When themotorcycle 10 is in operation, the power take-off gear 96 is rotated bythe flywheel 56, which in turn rotates the driven gear 104 causing thepower take-off sheave 106 to simultaneously rotate at rpms higher thanthat of the crankshaft 42. The sheave 106 in turn moves the drive belt86 causing the driven sheave 80 to rotate with the sheave 106, therebycausing the impeller of the supercharger 64 to rotate. The rotatingimpeller of the supercharger 64 draws in ambient air through the filter70, compresses it, and delivers it through the air delivery assembly 66to the intake manifold 48 of the engine 18. This compressed inductionfluid provides increased “boost,” or power, to the engine 18 throughoutits range of rpm.

As previously indicated, the air induction system of the presentinvention can be variously configured and integrated into a motorcyclein a variety of ways. One such suitable alternative is the superchargedmotorcycle 200 as partially shown in FIG. 9. The supercharged motorcycle200 is similar in many respects to the supercharged motorcycle 10described in detail above and therefore the supercharged motorcycle 200will only be described with respect to its differences. In particular,the drive train 202 of the motorcycle 200 utilizes a belt 204 to drivethe flywheel 206 off of the crankshaft 208. The air induction system 210of the motorcycle 200 utilizes a power take-off gear 212 that is drivenby the belt 204. In more detail, the power take-off gear 212 intermesheswith the belt 204 and is fixed relative to a transfer gear 214. Thetransfer gear 214 intermeshes with a driven gear 216. The driven gear216 is fixed relative to a driven sheave 218 that is entrained by adrive belt 220 that powers the supercharger of the air induction system210. The gears 212,214,216 and the sheave 218 are rotatably supported onthe side cover (not shown) and/or the support housing (not shown) of thesystem 210 in a manner similar to that detailed above with respect tothe air induction system 14.

A second preferred alternative embodiment of a power take-offsubassembly driven off of the drive train of the motorcycle is shown inthe supercharged motorcycle 300 partially illustrated in FIG. 10. Thesupercharged motorcycle 300 is virtually identical to the superchargedmotorcycle 200 described above. However, the supercharged motorcycle 300includes a drive train 302 that is driven by a chain 304 rather than abelt. A power take-off gear 306 for the air induction system 308intermeshes with the chain 304 between the crankshaft 310 and theflywheel 312.

A third preferred alternative embodiment of the power take-offsubassembly for an air induction system for a supercharged motorcycle isshown in the supercharged motorcycle 400 partially illustrated in FIGS.11–13. The air induction system for the supercharged motorcycle 400 isdriven off of the motorcycle's drive train by a drive assembly 402 (seeFIG. 11). The drive assembly 402 includes an indirect power take-offsubassembly 404 that is powered off of the drive trains's flywheel 406.The power take-off subassembly 404 is similar in many respects to thepreviously described power take-off subassembly 78, however, unlike thesubassembly 78, the power take-off subassembly 404 includes a breakawaycoupler assembly 408. The breakaway coupler aspects of the presentinvention are not limited to air induction system applications inmotorcycles, but equally apply to air induction systems for virtuallyany vehicle, including automobiles, marine vehicles, and the like. Theinventive breakaway coupler assembly 408 enables the motorcycle's drivetrain to continue operation in the event of catastrophic failure of theair induction system. In more detail, the breakaway coupler assembly 408normally drivingly couples a power take-off gear 410 and a drive gear412. The power take-off gear 410 intermeshes with the flywheel 406. Thedrive gear 412 is supported on a common shaft 414 with the powertake-off gear 410 and, as further detailed below, normally rotates withthe gear 410. The drive gear 412 intermeshes with a step-up transfergear 416 that is in turn fixed relative to a drive sheave 418 of thedrive assembly 402. The drive gear 412 is rotatably supported on theshaft 414 by a concentric bearing assembly 420 so that, for purposesthat will subsequently be described, the rotation of the shaft 414 isnot translated to the gear 412.

The breakaway coupler assembly 408 couples the power take-off gear 410and the drive gear 412 so that the gear 412 is normally drivinglycoupled to the gear 410 but under predetermined conditions, as will bedetailed below, the breakaway coupler assembly 408 enables the gears410,412 to rotate or cease to rotate independently of each other. Thebreakaway coupler assembly 408 includes a coupler disc 422, a pluralityof power take-off gear pegs 424, and a plurality of drive gear pegs 426.In more detail, the power take-off gear pegs 424 are fixed to the powertake-off gear 410 (although for illustrative purposes, the pegs 424 areshown removed from the gear 410 in FIGS. 12 and 13) in any suitablemanner, such as by welding or the like. The pegs 424 extend generallyperpendicularly from the gear 410 and are configured to engage the disc422 generally adjacent the circumference of the disc 422. For purposesthat will subsequently be described, the pegs 424 are further configuredand dimensioned so as not to engage the drive gear 412. In a similarmanner, the drive gear pegs 426 are fixed to the drive gear 412 andextend generally perpendicular therefrom to engage the disc 422. Forpurposes that will subsequently be described, the pegs 426 are radiallyoffset from the pegs 424 so as not to engage the pegs 424 if and whenthe gears 410,412 rotate independently of one another. It is importantthat the pegs 424,426 are configured so as not to engage one another,however, this could be accomplished in a number of ways, such asdimensioning the pegs 424,426 so that neither group of pegs 424,426extends beyond the longitudinal center of the disc 422.

The disc 422 is received between the gears 410,412 and shares the commonshaft 414 therewith. However, it is not important whether the disc 422is supported on the shaft 414 or spaced therefrom, as long as the shaft414 does not interfere with the breakaway function of the disc 422detailed below. The disc 422 is generally cylindrically shaped and isconfigured to receive the pegs 424,426 so that the gears 410,412 arenormally drivingly connected by the disc 422 under a variable torsionforce yet enables the gears 410,412 to drivingly disconnect to enablethe gears 410,412 to rotate freely and independently of one another whenthe torsion force exceeds a predetermined value. This predeterminedvalue will vary depending on the blower application, as well as thedrive assembly utilized for the blower and the vehicle's enginespecifications. However, the predetermined value should at leastslightly exceed the normal operational range of moment forces on thegears, such as occasioned by acceleration and deceleration of the blowerand engine. That is to say, a normal operational range of moment forcesis the range expected when the blower is operating free of foreignmaterial in the blower and drive assembly, the internal components ofthe blower, such as the bearings supporting the transmission andimpeller, are fully operational (e.g., the impeller is not contactingthe case, etc. In this regard, the illustrated disc 422 is formed froman elastomeric material presenting a sheer modulus sufficient tomaintain the driving coupling between the gears 410,412 under normaloperating conditions, yet substantially less than the sheer modulipresented by the gears 410,412 to enable the pegs 424,426 to shearthrough the disc 422 in the event of the air induction system locking up(e.g., catastrophic failure, etc.). The gears 410,412 are preferablyformed from steel or some other iron alloy (e.g., presenting a shearmodulus typically between fifty and one-hundred GPa). The disc 422 ispreferably formed from plastic and one suitable plastic is availablefrom the Dupont Company under the designation Hytrel® (e.g., having ashear modulus of less than 25 GPa). However, the disc 422 could beformed from materials other than plastic, such as synthetic rubbers(e.g., urethane, neoprene, etc.). In this manner, if the drive gear 412ceases to rotate, such as when the air induction system catastrophicallyfails, the power take-off gear pegs 424 will shear through the disc 422(without contacting the pegs 426) thus enabling the power take-off gear410 to continue rotating with the flywheel 406. It will be appreciatedthat continued rotation of the gear 410 is highly desirable in thatceasing rotation of the gear 410 will likely in turn cause the flywheel406 to cease rotation, which in turn can undesirably cause engine damageand the like. To a lesser extent, this breakaway coupling is desirableto prevent damage to the other components of the air induction system inthe event the power take-off gear 410 ceases to rotate.

The breakaway coupler assembly 408 is particularly well suited forHarley-Davidson® motorcycles wherein the air induction system is poweredoff of the flywheel. That is to say, flywheels on these motorcycles areknown to have a significant amount of play or “slop” and therefore havebeen thought to not be well suited for the tight tolerances demanded fordriving a power take-off gear for a supercharger. However, the breakawaycoupler assembly 408 provides a degree of safety, such as preventingdamage to the remaining components of the air induction system and drivetrain, in the event the driving intermeshing of the power take-off gear410 and the flywheel 406 is compromised. For example, the pegs 424 canshear through the disc 422 enabling the gear 410 to rotate freely withthe flywheel 406. In this event, the disc 422 (and one or more of theflywheel 406 and the gears 410,412 if necessary) can simply be replacedwithout having to replace or repair the relatively more expensive airinduction system components and drive train components. The breakawaycoupler assembly 408 further enables the advantage of a relativelyquieter drive assembly via the noise-dampening qualities of theelastomeric disc 422, as is desired from the typical Harley-Davidson®rider. However, the principles of this aspect of the present inventionare not limited to any particular make of motorcycle and as indicatedabove, are not limited to motorcycles. It is also within the ambit ofthe present invention to utilize various alternative configurations forthe breakaway coupler assembly. For example, the breakaway couplerassembly could be positioned between the supercharger drive sheave andthe supercharger transmission, or between the supercharger transmissionand the impeller. However, it is important that the assembly bepositioned between the supercharger impeller and the engine componentwhere the drive assembly takes power for the supercharger from andenable the drive components it couples together (e.g., gears, etc.) torotate freely and independently of one another in the event the torsionforces therebetween exceed the normal operating conditions, such as areexperienced in the event of a catastrophic failure of the air inductionsystem.

The preferred forms of the invention described above are to be used asillustration only, and should not be utilized in a limiting sense ininterpreting the scope of the present invention. Obvious modificationsto the exemplary embodiments, as hereinabove set forth, could be readilymade by those skilled in the art without departing from the spirit ofthe present invention.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

1. A supercharged motorcycle comprising: a front wheel; a rear wheellongitudinally spaced from said front wheel; an engine including arotatable crankshaft generally positioned between said wheels, saidengine presenting opposite left and right sides corresponding to sidesof the motorcycle, said engine further including an air intake; and anair induction system operable to deliver compressed induction fluid tothe air intake, said air induction system including a superchargeradjacent one of the sides of the engine and a drive assembly drivinglyconnecting the supercharger relative to the crankshaft, saidsupercharger being longitudinally spaced forward of said crankshaft todefine a fore area therebetween with the drive assembly spanning thefore area, said air induction system further including a intake fluidline connected between the supercharger and the air intake, said intakefluid line projecting forwardly from the supercharger and extendingforwardly of the engine and across the front of the engine to the engineside opposite the supercharger for transferring the compressed inductionfluid from the supercharger to the air intake.
 2. The motorcycle asclaimed in claim 1, said supercharger comprising a centrifugalsupercharger including a self-contained dedicated lubrication system inwhich all of the lubricant is contained entirely within thesupercharger.
 3. The motorcycle as claimed in claim 1; and a drive traindrivingly interconnecting said crankshaft and said rear wheel andincluding a rotatable driven element and an endless element drivinglyinterconnecting said crankshaft and said driven element, said drivenelement being aftwardly and longitudinally spaced from said crankshaftto thereby define an aft area between said crankshaft and said drivenelement.
 4. A supercharged motorcycle comprising: a front wheel; a rearwheel longitudinally spaced from said front wheel; an engine including arotatable crankshaft generally positioned between said wheels; and anair induction system operable to deliver compressed induction fluid tothe engine, said air induction system including a supercharger and adrive assembly drivingly connecting the supercharger relative to thecrankshaft, said supercharger being longitudinally spaced forward ofsaid crankshaft to define a fore area therebetween with the driveassembly spanning the fore area, a drive train drivingly interconnectingsaid crankshaft and said rear wheel and including a rotatable drivenelement and an endless element drivingly interconnecting said crankshaftand said driven element, said driven element being aftwardly andlongitudinally spaced from said crankshaft to thereby define an aft areabetween said crankshaft and said driven element, said drive assemblyincluding a foremost rotatable supercharger-driving componentlongitudinally spaced from said crankshaft and positioned in or forwardof the fore area, and an aftmost rotatable power take-off componentlongitudinally spaced from said crankshaft and positioned in or behindthe aft area so that the drive assembly extends into and spans betweenthe fore and aft areas.
 5. The motorcycle as claimed in claim 4, saidpower take-off component drivingly intermeshing with one of said endlessand driven elements.
 6. The motorcycle as claimed in claim 5, said oneof said endless and driven elements being said driven element, saiddriven element comprising a toothed flywheel.
 7. The motorcycle asclaimed in claim 4, said drive assembly including an endless driveelement drivingly entraining said rotatable components.
 8. Themotorcycle as claimed in claim 1; and a side cover at least partiallyenclosing said crankshaft, said air induction system including agenerally flat support bracket supporting said supercharger on said sidecover.
 9. The motorcycle as claimed in claim 1, said air inductionsystem including an intercooler fluidly coupled between the superchargerand engine and operable to cool the compressed induction fluid.
 10. Themotorcycle as claimed in claim 1, said air induction system including anintercooler for cooling the compressed induction fluid, at least aportion of the intercooler being forward of the engine.
 11. Themotorcycle as claimed in claim 1, said rotatable crankshaft situated ona first side of the motorcycle.
 12. The motorcycle as claimed in claim11, said air intake adjacent a second side of the motorcycle oppositethe first side.
 13. The motorcycle as claimed in claim 12, saidsupercharger being positioned on the first side of the motorcycle.
 14. Amotorcycle for mounted operation by a rider, wherein the motorcycle isretrofit with an aftermarket supercharging system, said motorcyclecomprising: a chassis operable to be mounted by the rider in a normaloperating position and including a front wheel, a rear wheellongitudinally spaced from said front wheel, a frame supported betweenthe wheels, a gas tank spaced between said wheels, a seat positioned aftof the gas tank and configured to support the rider in the normaloperating position, and a pair of foot supports spaced on either side ofthe frame and positioned generally below the gas tank and the seat; anengine including a rotatable crankshaft generally positioned betweensaid wheels, said chassis and engine cooperating to define a pair oforiginal leg-receiving areas spaced on either side of the chassis andeach being operable to receive a corresponding leg of the rider when therider is mounted on the seat in the normal operating position, each ofsaid foot supports presenting an innermost edge cooperating with achassis contact point to define a fore-and-aft extending plane, each ofsaid original leg-receiving areas being generally defined by acurvilinear leg path projecting along the corresponding plane andextending between said seat and a respective one of said foot supports;and an air induction system operable to deliver compressed inductionfluid to the engine and including a supercharger and a drive assemblydrivingly connecting the supercharger relative to the engine to supplypower from the engine to the supercharger, said entire air inductionsystem being positioned outside of the original leg-receiving areas withat least a portion of the air induction system extending between saidleg paths, at least a portion of the supercharger being spaced laterallyoutward from the respective plane and forward of the leg-receiving areaso the at least a portion of the supercharger is in front of theleg-receiving area.
 15. The motorcycle as claimed in claim 14, said atleast a portion of the air induction system being positioned entirelyinboard of the leg paths.
 16. The motorcycle as claimed in claim 14, oneof said frame and gas tank defining a pair of laterally outermostrider-engaging contact points oppositely spaced on either side of thechassis that engage the rider's legs when the rider is mounted on theseat in the normal operating position, each of said contact points beingpositioned along a respective one of said leg paths, each of said footsupports presenting a foot-supporting surface for supporting a foot ofthe rider when the rider is mounted of the seat in the normal operatingposition, each of said foot-supporting surfaces defining an outermostedge laterally spaced from said frame and an innermost edge adjacentsaid frame, each of said innermost edges lying in a common plane with arespective one of said contact points, each of said leg paths lying in arespective one of said common planes.
 17. The motorcycle as claimed inclaim 16; and a drive train drivingly interconnecting said crankshaftand said rear wheel and including a rotatable driven element and anendless element drivingly interconnecting said crankshaft and saiddriven element, said supercharger including a rotatable impelleroperable to compress induction fluid for the engine when rotated, saiddrive assembly drivingly interconnecting said rotatable impeller and oneof said driven and endless elements, said drive assembly beingpositioned entirely inboard of said common planes so as to not engagethe rider when the rider is mounted on the seat in the normal operatingposition.
 18. The motorcycle as claimed in claim 17, said superchargerbeing forwardly and longitudinally spaced from said crankshaft tothereby define a fore area therebetween.
 19. The motorcycle as claimedin claim 18, said driven element being aftwardly and longitudinallyspaced from said crankshaft to thereby define an aft area therebetween.20. A supercharged motorcycle for mounted operation by a rider, saidmotorcycle comprising: a chassis operable to be mounted by the rider ina normal operating position and including a front wheel, a rear wheellongitudinally spaced from said front wheel, a frame supported betweenthe wheels, a gas tank spaced between said wheels, a seat positioned aftof the gas tank and configured to support the rider in the normaloperating position, and a pair of foot supports spaced on either side ofthe frame and positioned generally below the gas tank and the seat; anengine including a rotatable crankshaft generally positioned betweensaid wheels, said chassis and engine cooperating to define a pair ofleg-receiving areas spaced on either side of the chassis and each beingoperable to receive a corresponding leg of the rider when the rider ismounted on the seat in the normal operating position, each of saidleg-receiving areas being generally defined by a curvilinear leg pathextending between said seat and a respective one of said foot supports;and an air induction system operable to deliver compressed inductionfluid to the engine and including a supercharger and a drive assemblydrivingly connecting the supercharger relative to the engine to supplypower from the engine to the supercharger, said entire air inductionsystem being positioned outside of the leg-receiving areas with at leasta portion of the air induction system extending between said leg paths,one of said frame and gas tank defining a pair of laterally outermostrider-engaging contact points oppositely spaced on either side of thechassis that engage the rider's legs when the rider is mounted on theseat in the normal operating position, each of said contact points beingpositioned along a respective one of said leg paths, each of said footsupports presenting a foot-supporting surface for supporting a foot ofthe rider when the rider is mounted on the seat in the normal operatingposition, each of said foot-supporting surfaces defining an outermostedge laterally spaced from said frame and an innermost edge adjacentsaid frame, each of said innermost edges lying in a common plane with arespective one of said contact points, each of said leg paths lying in arespective one of said common planes, a drive train drivinglyinterconnecting said crankshaft and said rear wheel and including arotatable driven element and an endless element drivinglyinterconnecting said crankshaft and said driven element, saidsupercharger including a rotatable impeller operable to compressinduction fluid for the engine when rotated, said drive assemblydrivingly interconnecting said rotatable impeller and one of said drivenand endless elements, said drive assembly being positioned entirelyinboard of said common planes so as to not engage the rider when therider is mounted on the seat in the normal operating position, saidsupercharger being forwardly and longitudinally spaced from saidcrankshaft to thereby define a fore area therebetween, said drivenelement being aftwardly and longitudinally spaced from said crankshaftto thereby define an aft area therebetween, said drive assemblyincluding a foremost rotatable supercharger-driving componentlongitudinally spaced from said crankshaft and positioned in or forwardof the fore area, and an aftmost rotatable power take-off componentlongitudinally spaced from said crankshaft and positioned in or behindthe aft area so that the drive assembly extends into and spans betweenthe fore and aft areas.
 21. The motorcycle as claimed in claim 20, saidpower take-off component drivingly intermeshing with one of said endlessand driven elements.
 22. The motorcycle as claimed in claim 21, said oneof said endless and driven elements being said driven element, saiddriven element comprising a toothed flywheel.
 23. The motorcycle asclaimed in claim 20, said drive assembly including an endless driveelement drivingly entraining said rotatable components.
 24. Themotorcycle as claimed in claim 14; and a side cover at least partiallyenclosing said crankshaft, said air induction system including agenerally flat support bracket supporting said supercharger on said sidecover, at least a portion of said support bracket extending between saidleg paths with said at least a portion of said support bracket beingpositioned entirely inboard of the leg paths.
 25. A superchargedmotorcycle comprising: a chassis operable to be mounted by a rider andincluding a front wheel and a rear wheel longitudinally spaced from saidfront wheel; an engine including a rotatable crankshaft generallypositioned between said wheels, said engine presenting opposite left andright sides corresponding to sides of the motorcycle, said enginefurther including an air intake; a drive train drivingly interconnectingsaid crankshaft and said rear wheel and including a rotatable drivenelement longitudinally spaced from said crankshaft and an endlesselement drivingly interconnecting said crankshaft and said drivenelement; and an air induction system operable to deliver compressedinduction fluid to the air intake and including a supercharger adjacentone of the sides of the engine and a drive assembly, said drive assemblydrivingly interconnecting said drive train and said supercharger andincluding an indirect power take-off component drivingly engaging one ofsaid driven and endless elements, said air induction system furtherincluding an intake fluid line connected between the supercharger andthe air intake, said intake fluid line projecting forwardly from thesupercharger and extending forwardly of the engine and across the frontof the engine to the engine side opposite the supercharger fortransferring the compressed induction fluid from the supercharger to theair intake.
 26. The motorcycle as claimed in claim 25, said one of saiddriven and endless elements being said driven element, said drivenelement comprising a flywheel.
 27. The motorcycle as claimed in claim25, one of said driven and endless elements being said endless element.28. The motorcycle as claimed in claim 27, said endless elementcomprising a cogged belt.
 29. The motorcycle as claimed in claim 27,said endless element comprising a chain.
 30. The motorcycle as claimedin claim 25, said supercharger including a rotatable impeller thatcompresses induction fluid for the engine when rotated.
 31. Themotorcycle as claimed in claim 30, said supercharger being forwardly andlongitudinally spaced from said crankshaft to thereby define a fore areatherebetween.
 32. The motorcycle as claimed in claim 31, said drivenelement being aftwardly and longitudinally spaced from said crankshaftto thereby define an aft area therebetween.
 33. The motorcycle asclaimed in claim 25, said air induction system including an intercoolerfor cooling the Compressed induction fluid, at least a portion of theintercooler being forward of the engine.
 34. The motorcycle as claimedin claim 25, said rotatable crankshaft situated on a fist side of themotorcycle.
 35. The motorcycle as claimed in claim 34, said air intakeadjacent a second side of the motorcycle opposite the first side. 36.The motorcycle as claimed in claim 35, said supercharger beingpositioned on the first side of the motorcycle.
 37. A superchargedmotorcycle comprising: a chassis operable to be mounted by a rider andincluding a front wheel and a rear wheel longitudinally spaced from saidfront wheel; an engine including a rotatable crankshaft generallypositioned between said wheels; a drive train drivingly interconnectingsaid crankshaft and said rear wheel and including a rotatable drivenelement longitudinally spaced from said crankshaft and an endlesselement drivingly interconnecting said crankshaft and said drivenelement; and an air induction system operable to deliver compressedinduction fluid to the engine and including a supercharger and a driveassembly, said drive assembly drivingly interconnecting said drive trainand said supercharger and including an indirect power take-off componentdrivingly engaging one of said driven and endless elements, saidsupercharger including a rotatable impeller that compresses inductionfluid for the engine when rotated, said supercharger being forwardly andlongitudinally spaced from said crankshaft to thereby define a fore areatherebetween, said driven element being aftwardly and longitudinallyspaced from said crankshaft to thereby define an aft area therebetween,said drive assembly including a foremost rotatable supercharger-drivingcomponent longitudinally spaced from said crankshaft and positioned inor forward of the fore area, said power take-off component beinglongitudinally spaced from said crankshaft and positioned in or behindthe aft area so that the drive assembly extends into and spans betweenthe fore and aft areas.
 38. The motorcycle as claimed in claim 25, saiddrive assembly including a rotatable supercharger-driving componentspaced from said power take-off component, said drive assembly furtherincluding an endless drive element drivingly entraining saidsupercharger-driving and power take-off components.
 39. The motorcycleas claimed in claim 38; and a side cover at least partially enclosingsaid crankshaft, said power take-off component being rotatably supportedon said side cover.
 40. The motorcycle as claimed in claim 39, said airinduction system including a generally flat support bracket supportingsaid supercharger on said side cover.
 41. The motorcycle as claimed inclaim 40, said air induction system including an intercooler positioneddownstream of said supercharger and upstream of said engine.
 42. Asupercharged motorcycle comprising: a front wheel; a rear wheellongitudinally spaced from said front wheel; an engine including arotatable crankshaft and an air intake, said engine presenting oppositeleft and right sides corresponding to sides of the motorcycle; and anair induction system operable to deliver compressed induction fluid tothe air intake, said air induction system including a superchargeradjacent one of the sides of the engine and a drive assembly drivinglyconnecting the supercharger relative to the crankshaft, said airinduction system further including an intake fluid line connectedbetween the supercharger and the air intake, said intake fluid lineprojecting forwardly from the supercharger and extending forwardly ofthe engine and across the front of the engine to the engine sideopposite the supercharger for transferring the compressed inductionfluid from the supercharger to the air intake.
 43. The motorcycle asclaimed in claim 42, a drive train drivingly interconnecting saidcrankshaft and said rear wheel and including a rotatable driven elementlongitudinally spaced from said crankshaft and an endless elementdrivingly interconnecting said crankshaft and said driven element, saiddrive assembly drivingly interconnecting said drive train and saidsupercharger and including an indirect power take-off componentdrivingly engaging one of said driven and endless elements.
 44. Themotorcycle as claimed in claim 43, one of said driven and endlesselements being said endless element.
 45. The motorcycle as claimed inclaim 44, said endless element comprising a cogged belt.
 46. Themotorcycle as claimed in claim 43, said supercharger including arotatable impeller that compresses induction fluid for the engine whenrotated.
 47. The motorcycle as claimed in claim 46, said superchargerbeing forwardly and longitudinally spaced from said crankshaft tothereby define a fore area therebetween.
 48. The motorcycle as claimedin claim 47, said driven element being aftwardly and longitudinallyspaced from said crankshaft to thereby define an aft area therebetween.49. The motorcycle as claimed in claim 48, said drive assembly includinga foremost rotatable supercharger-driving component longitudinallyspaced from said crankshaft and positioned in or forward of the forearea, said power take-off component being longitudinally spaced fromsaid crankshaft and positioned in or behind the aft area so that thedrive assembly extends into and spans between the fore and aft areas.50. The motorcycle as claimed in claim 43, said drive assembly includinga rotatable supercharger-driving component spaced from said powertake-off component, said drive assembly further including an endlessdrive element drivingly entraining said supercharger-driving and powertake-off components.
 51. The motorcycle as claimed in claim 50; and aside cover at least partially enclosing said crankshaft, said powertake-off component being rotatably supported on said side cover.
 52. Themotorcycle as claimed in claim 51, said air induction system including agenerally flat support bracket supporting said supercharger on said sidecover.
 53. The motorcycle as claimed in claim 52, said air inductionsystem including an intercooler fluidly coupled between the superchargerand engine and operable to cool the compressed induction fluid.
 54. Themotorcycle as claimed in claim 42, said air induction system includingan intercooler for cooling the compressed induction fluid, at least aportion of the intercooler being forward of the engine.
 55. Themotorcycle as claimed in claim 42, said rotatable crankshaft situated ona first side of the motorcycle.
 56. The motorcycle as claimed in claim55, said air intake adjacent a second side of the motorcycle oppositethe first side.
 57. The motorcycle as claimed in claim 56, saidsupercharger being positioned on the first side of the motorcycle.